1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *  fs/partitions/mac.c
  4 *
  5 *  Code extracted from drivers/block/genhd.c
  6 *  Copyright (C) 1991-1998  Linus Torvalds
  7 *  Re-organised Feb 1998 Russell King
  8 */
  9
 10#include <linux/ctype.h>
 11#include "check.h"
 12#include "mac.h"
 13
 14#ifdef CONFIG_PPC_PMAC
 15#include <asm/machdep.h>
 16extern void note_bootable_part(dev_t dev, int part, int goodness);
 17#endif
 18
 19/*
 20 * Code to understand MacOS partition tables.
 21 */
 22
 23#ifdef CONFIG_PPC_PMAC
 24static inline void mac_fix_string(char *stg, int len)
 25{
 26	int i;
 27
 28	for (i = len - 1; i >= 0 && stg[i] == ' '; i--)
 29		stg[i] = 0;
 30}
 31#endif
 32
 33int mac_partition(struct parsed_partitions *state)
 34{
 35	Sector sect;
 36	unsigned char *data;
 37	int slot, blocks_in_map;
 38	unsigned secsize, datasize, partoffset;
 39#ifdef CONFIG_PPC_PMAC
 40	int found_root = 0;
 41	int found_root_goodness = 0;
 42#endif
 43	struct mac_partition *part;
 44	struct mac_driver_desc *md;
 45
 46	/* Get 0th block and look at the first partition map entry. */
 47	md = read_part_sector(state, 0, &sect);
 48	if (!md)
 49		return -1;
 50	if (be16_to_cpu(md->signature) != MAC_DRIVER_MAGIC) {
 51		put_dev_sector(sect);
 52		return 0;
 53	}
 54	secsize = be16_to_cpu(md->block_size);
 55	put_dev_sector(sect);
 56
 57	/*
 58	 * If the "block size" is not a power of 2, things get weird - we might
 59	 * end up with a partition straddling a sector boundary, so we wouldn't
 60	 * be able to read a partition entry with read_part_sector().
 61	 * Real block sizes are probably (?) powers of two, so just require
 62	 * that.
 63	 */
 64	if (!is_power_of_2(secsize))
 65		return -1;
 66	datasize = round_down(secsize, 512);
 67	data = read_part_sector(state, datasize / 512, &sect);
 68	if (!data)
 69		return -1;
 70	partoffset = secsize % 512;
 71	if (partoffset + sizeof(*part) > datasize) {
 72		put_dev_sector(sect);
 73		return -1;
 74	}
 75	part = (struct mac_partition *) (data + partoffset);
 76	if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC) {
 77		put_dev_sector(sect);
 78		return 0;		/* not a MacOS disk */
 79	}
 80	blocks_in_map = be32_to_cpu(part->map_count);
 81	if (blocks_in_map < 0 || blocks_in_map >= DISK_MAX_PARTS) {
 82		put_dev_sector(sect);
 83		return 0;
 84	}
 85
 86	if (blocks_in_map >= state->limit)
 87		blocks_in_map = state->limit - 1;
 88
 89	strlcat(state->pp_buf, " [mac]", PAGE_SIZE);
 90	for (slot = 1; slot <= blocks_in_map; ++slot) {
 91		int pos = slot * secsize;
 92		put_dev_sector(sect);
 93		data = read_part_sector(state, pos/512, &sect);
 94		if (!data)
 95			return -1;
 96		part = (struct mac_partition *) (data + pos%512);
 97		if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC)
 98			break;
 99		put_partition(state, slot,
100			be32_to_cpu(part->start_block) * (secsize/512),
101			be32_to_cpu(part->block_count) * (secsize/512));
102
103		if (!strncasecmp(part->type, "Linux_RAID", 10))
104			state->parts[slot].flags = ADDPART_FLAG_RAID;
105#ifdef CONFIG_PPC_PMAC
106		/*
107		 * If this is the first bootable partition, tell the
108		 * setup code, in case it wants to make this the root.
109		 */
110		if (machine_is(powermac)) {
111			int goodness = 0;
112
113			mac_fix_string(part->processor, 16);
114			mac_fix_string(part->name, 32);
115			mac_fix_string(part->type, 32);					
116		    
117			if ((be32_to_cpu(part->status) & MAC_STATUS_BOOTABLE)
118			    && strcasecmp(part->processor, "powerpc") == 0)
119				goodness++;
120
121			if (strcasecmp(part->type, "Apple_UNIX_SVR2") == 0
122			    || (strncasecmp(part->type, "Linux", 5) == 0
123			        && strcasecmp(part->type, "Linux_swap") != 0)) {
124				int i, l;
125
126				goodness++;
127				l = strnlen(part->name, sizeof(part->name));
128				if (strncmp(part->name, "/", sizeof(part->name)) == 0)
129					goodness++;
130				for (i = 0; i <= l - 4; ++i) {
131					if (strncasecmp(part->name + i, "root",
132						     4) == 0) {
133						goodness += 2;
134						break;
135					}
136				}
137				if (strncasecmp(part->name, "swap", 4) == 0)
138					goodness--;
139			}
140
141			if (goodness > found_root_goodness) {
142				found_root = slot;
143				found_root_goodness = goodness;
144			}
145		}
146#endif /* CONFIG_PPC_PMAC */
147	}
148#ifdef CONFIG_PPC_PMAC
149	if (found_root_goodness)
150		note_bootable_part(state->disk->part0->bd_dev, found_root,
151				   found_root_goodness);
152#endif
153
154	put_dev_sector(sect);
155	strlcat(state->pp_buf, "\n", PAGE_SIZE);
156	return 1;
157}